Dear,

I have projects and users but I can't create a membership between a project and a user by using API request.

Here is an attempt 

curl -s -H "Content-Type: application/json" \
 --data-urlencode 'filters=[{"project":{"operator":"=","values":["10"]}}]' \
-d '{"_links":{"principal":{"name":"4"},"principal":{"name":"4"},"roles":{"name":"4"}}}'  \
-u apikey:$API_KEY \
-X POST 'http://192.168.1.21:8080/openproject/api/v3/memberships?'  | jq  .

Here is the answer:

{
  "_type": "Error",
  "errorIdentifier": "urn:openproject-org:api:v3:errors:InvalidRequestBody",
  "message": "The request could not be parsed as JSON.",
  "_embedded": {
    "details": {
      "parseError": "expected false () at line 1, column 2"
    }
  }
}

I do not understand the answer as my json is correct (validated by a json validator)

Can you give me a hint to resolve my issue ? (or an example)

I am using OpenProject 10.4.1

Thanks a lot

Kind regards

Xerviami